Effect of N/Z in pre-scission neutron multiplicity for ^16,18O+¹⁹⁸Pt systems

This paper reports the summary of the experimental results of pre-scission neutron multiplicities from four compound nuclei, namely ^{210,212,214,216}Rn, and statistical model analysis of the corresponding data. The compound nuclei ^{210,212,214,216}Rn having N/Z values as 1.441, 1.465, 1.488, 1.511 respectively are populated through the ^16,18O+^194,198Pt reactions at excitation energies of 50, 61, 71.7 and 79 MeV. The measured neutron multiplicities are further analyzed with the statistical model of nuclear decay where fission hindrance due to nuclear dissipation is considered. The N/Z dependence of the dissipation strength at lowest excitation energy of the compound nuclei suggests shell closure effects. However, such effects are not observed at higher excitations where the variation of the dissipation strength with N/Z does not show any specific trend. The variation of N/Z in fission time scale is also shown. (authors)